Engine piston



7 Oct 30, 1928. 1,689,953

M. H, LUTZ; JR

ENGINE PISTON Filed July 25, 1927 Martin H Luiz v v B V c I I 1% o ATTORNEY.

contact- IHIGSSUTQ-bQ EWOGII the cylinder. 'wall" possi billty -.o

Patented Qct; 30, 1928.

i f ,i A-m s eientities: nl d f meme ntimidation medqu as l is to yiirovide an inn to prof vide co struction which. Wfl toniaticaliy take care of compression by .JIlCI'QtuS1Dg the and that elenientaofthe piston engaged by it; to giirovile a construction in whiclrthe .ithe-joe'ctn mice of piston slap will be reduced to a minimumit' notavoided altogether; to provide apiston which will be 1i ght in weight and of a character-to provide a long life as well] as to prevent scoring of the cylinders; toprovide a piston in which the cylinder wear attendingits use will be evenly distril iuted throughout, so thatrthe cylinder may remain true and thus avoid the necessityforte-boring; and to provide a piston construction in which vibration will be materially reduced, carbon deposits prac-' tically eliminated and a material saving in oil etiected. h

\Vith this object in view, the invention c011- sists in a constructionand combination oil ed with the latter by a compression ring 12 but movable with respect to the body por tion. Diametrically the body portion is materially reduced in diameter below that of the cylinder.

terially less than that of the cylinder 13 so that atno time, during its operation, may the body" portion be brought into contact with the cylinder wall. In the illustrated embodiment an, irregular body portion is illustrated as'constituting ap ood design but the essential feature is that it shall be ma- At the crank case end, the cylinder car ries an oil ring Hand attendant expansion rings 15 but specific description of these is omitted because oftheir being identical with that shown in Patent No. 1,469,656, dated 'October 2, 1923. I I

y T he body portion ottlie cylinder at the head end is provided with a peripheral "these two eron 1 927. seriaL'No; 208,275.

lishaped:g'roove.16andthe head of the cyl;

inder. with a similar; groove 17, the compres 3': l2 having' lips; 1 8 and 519 engaging grooves. "lhe ad cent side walls ody .por

,of the grooves in theb 11 l. to toe axis of the ad in, plan nder. which d os to said,

wall iii the body poi tion. -By this construction, any tendency to r'orce the head toward the body portion or the cylinder tends to diainetrical expansion of the compression ring by virtue of the inclined coasting surfacesof the grooves and lips. a

on and in' the p the reinaining walls axis, the nchjnedwall -.:the opposite angle to' V The compression ringis split diametrically so that it thereby comprises complemental sections of which the joints between the two are overlapping as indicated at 20 and the two complemental sections are yieldingly impolled into contact with the cylinder walljby' a split expansion ring 21 seated in an inner peripheral groove in the two sections.

The head 11 is yieldingly impelled away from the body portionlO by interposedconr .pression springs 22 of which the extremities engage button-like projections 23 formed on the body portionand head respectively.

* During the firing and compression strokes,

the pressure exerted on the head 11 will tend 'tOflfOlCB it toward the body portion and theretore effect diametrical expansion of the compression ring into firm contact with the cyl inder wall, thus maintaining a tight 01m at I these periods inthe cycle of operation. During the scayenging and intake strokes, the

head 11 will not be subject to pressure and will recede from the body portion because of the springs The compression ring will then be subject to the pressure of the ex 'ieir sion ring which, however, will keep it in contact with the cylinder wall to prevent the passage of oil' around it and because of its ,wedge-shaped connection with the piston body and head will tend to retain the two concentric with it, so that'there will be no A tendency of any part of the piston or head to come in contact with the cylinder wall.

The invention having been described, what claimed as new and useful is: c 1. A piston comprising a body portion, a head separate from the body portion, the pisston and the head being formed with periphcral grooves having side walls disposed at acute angles; to the axls of the piston, the Wall in the head being at the opposite angle from that in the body portion, and a compression ring bounding the head and a part of the body portion and having lips conforming in shape to the shape of the grooves in the same.

:2. A piston comprising a body portion, a head separate from the body portion, the piston and the head being formed with peripheral grooves having side walls disposed at acute angles to the axis of the piston, the wall in the head being at the opposite angle from that in the body portion, and a compression ring bounding the head and a part of the body portion and having lips conforming in shape to the shape of the grooves in the same and compression springs interposed between the head and the body portion.

of the body portion and having lips conforming in shape to the shape of the grooves in the same, and compression springs comprising coinpleniental sections and a split, expansion ring seated in a groove in the inner periphery of said sections.

In testimony whereof he aflixes his signaiure.

MARTIN H. LUTZ, JR 

